Lehman's bankruptcy sparked genuine fears in the US that the country's entire financial system could collapse. It led to a crazy scramble by senior bankers and politicians to insulate the industry, and the wider economy, from the threat of contagion.

One of the most crucial figures during this period was Henry "Hank" Paulson, the United States Treasury Secretary. He was the most senior politician with responsibility for the financial industry and the conduit between the US government and big banks.

Lehman collapsed on September 15, and Paulson's schedule in the days following provides a glimpse into the chaos

The schedule, printed in Andrew Ross Sorkin's epic account of the crisis, Too Big To Fail, reveals just how crazily busy and hectic the days around Lehman's collapse were. Paulson, who was Treasury Secretary between 2006 and 2009, took a staggering 42 calls and meetings between 7.10 a.m. and 1.20 p.m, and a total of 69 over the course of the entire day.

Those calls included one to then-President George Bush, several to Federal Reserve Chair Ben Bernanke, and New York Fed head Tim Geithner, as well as conversations with Lehman CEO Dick Fuld, Goldman Sachs boss Lloyd Blankfein, and JPMorgan's Jamie Dimon.

"Paulson's calendar and call log illustrates the frantic scramble," Sorkin wrote underneath the schedule, noting as well that the log "does not reflect calls on his cell phone or home phone."

Check it out below, with the first half of the day reproduced in full:

7.10 a.m. to 7.20 a.m. — Call from President George W. Bush

7.20 to 7.40 — Call from Tim Geithner, New York Federal Reserve Chairman